Nutrition Overview Flashcards
(110 cards)
1
Q
Nutrient definition
A
Chemical substance in food
Provides sometimes energy and body balance
2
Q
Types of nutrients
A
Macronutrients : carbohydrates, fats and proteins (water)
Micronutrients : vitamins, minerals
3
Q
Nutrients that provide energy
A
Carbohydrates, proteins, fats
Alcohol too even though not a nutrient
4
Q
Variables affecting nutrients requirements
A
Age Gender Activity level State of nutrition Climate (more nutrients when cold) Health
5
Q
Recommended daily allowance of nutrients
A
70kg Man = 2900kcal/day
50kg woman = 2100 kcal/day
6
Q
Energy requirements
A
Basal metabolism rate => energy needed to survive , taken in resting state
Specific dynamic action => energy used when digesting
Physical activity => patient lifestyle
7
Q
Micronutrients categories
A
Vitamins (organic)
Minerals ( inorganic)
Designer vitamins
8
Q
Are vitamins essential
A
Yes because not produced in body
9
Q
Fat soluble vitamins
A
A
D
E
K
10
Q
How are fat soluble vitamins transported in plasma
A
By transporters
11
Q
Where are fat soluble vitamins stored
A
Adipose tissue and liver
12
Q
Why are fat soluble vitamins not readily excreted in urine
A
Bound to plasma protein for transport so too big to be filtered
13
Q
Vitamin A main compound
A
Retinol which can produce retinoic acid
14
Q
Source of vitamin A
A
Yellow dark green vegetables with carotene
15
Q
Uses of vitamin A
A
Helps in vision because found in opsin which is involved in night vision
Helps in growth ( bones , CNS )
Helps in reproduction by maintaining fœtus and promote spermatogenesis
Improve epithelium
Antioxidant- protect against reactive species
16
Q
Diseases related to vit A deficiency
A
Night blindness ( lack of adaptation to darkness)
Xerophthalmia - lens keratization
Acne/psoriasis - lack of normal epitheliazation and thickening skin
17
Q
Amount of vitamin A to reach toxicity
A
7.5mg/day
18
Q
Symptoms of hypervitaminoses A
A
Dry itchy skin
Hepatomegaly
Increased intracranial pressure
Congenital malformation\
19
Q
Form of vitamin A stored in liver
A
Retinyl ester
20
Q
Main function of vit K
A
Posttranslational regulation of clotting blood factor
21
Q
Functions of vit K
A
Helps in synthesis of prothrombin and blood clotting factor (II,VII, IX,X)
22
Q
Source of vit K
A
Cabbage Kale Spinach Egg yolk Liver Synthesis by bacteria in gut
23
Q
Deficiency of vit K
A
Rare
Lead to bleeding tendency
24
Q
Why should you give vit k as single shot prophylaxis to new born
A
Because they are born sterile with no bacteria in gut responsible for vit k synthesis. Need it while they get enough of vit k from breast feeding
25
Vitamin k toxicity
Hemolytic anemia
26
Vitamin E functions
Antioxidants especially for polyunsaturated FAs
27
Source of vit E
Vegetable oils
| Liver eggs
28
Deficiency of vit E
Seen in premature infants or adult with defective lipid absorption and and transport
29
Vit E toxicity
Least toxic
30
Vitamin D sources
D2 found in plants
D3 found in animal tissues
Can be synthesized under light exposition
31
Vit D functions
Intestinal absorption of calcium And phosphate
32
Vit D deficiency
Nutritional ricket ( growing bone disease in children ) with soft pliable bone
Osteomalacia in adults ( lack of sunlight exposure)
Renal osteodystrophy: chronic renal failure leading to failure of activation of vit D
Hypoparathyroidism: hypocalcemia due to lack of of parathyroid hormones
33
Water soluble vitamins are mostly
Coenzymes
34
2 groups of vitamins soluble
Vit C
| Vit B
35
Vit b1 molécule
Thiamine
36
Vit b1 act as coenzyme in
Transketolase
| Oxidative decarboxylation of alpha keto acids
37
Thiamine deficiency
Leads to decreased ATP and therefore cellular impairment
Beriberi: tachycardia, vomiting , convulsion, death, progressive paralysis in adults
Wernicke korsakoff syndrome : seen in alcoholics with apathy, loss of memory, ataxia,
38
Vitamin b2 name
Riboflavin
39
Is vit b2 deficiency associated with disease ?
No major disease
| Just cheilosis, glossitis
40
Vit b3 name
Niacin
41
Source of vit b3 niacin
```
Grain
Cereal
Milk
Lean meats
Liver
```
42
Niacin deficiency
Pellagra - skin disease involving GIT And CNS => Dermatitis, Diarrhea, Dementia
43
Which vitamin can use in hyperlipideamia
Vit b3 niacin by inhibiting lipolysis
44
Vit B9 molécule
Folic acid
45
Main vitamin deficiency in the work
Vit B9 or B12 deficiency
46
Cause of folate deficiency
Pregnancy
Lactation
Poor absorption at small intestine due toalcoholism o
47
Folate deficiency consequences
Megaloblastic anemia
Neural tube defects
48
Vitb12 molecule
Cobalamin
49
Source of vitb12
Animals only
50
Vit b12 deficiency
Megaloblastic anemia due to lack of tetrahydrofolate necessary for thymine synthesis
Pernicious anemia ( malabsorption of vitb12 die to lack of intrinsic factor ) presents as anemia with neuropsychiatric symptoms
51
Vit c molécule
Ascorbic acid
52
Vit c function
Normal connective tissue maintenance ( collagen)
Wound healing
Facilitate iron absorption
Antioxidants
53
Vit c defiency
Scurvy : sponge and gums loose teeth’s, swollen joints and anemia
54
Protein energy malnutrition epidemiology
Children in developing countries who lack food and clean water
55
Precipitating factors of protein energy malnutrition
Famine
poverty
Inappropriate breastfeeding
Wrong concepts about nutrition
56
Disease caused by protein energy malnutrition
Quest your car
57
Causes of kwashiorkor
Sudden and Early Weaning of child ( due in general to successive pregnancy)
They metabolize proteins before adipose tissue
58
Symptoms of kwashiorkor
```
Psychomotor
Edema
moon face
Hair changes
Skin de pigmentation
Anemia
Thin legs
```
59
Storage of iron
Ferritin and hemosiderin
60
Lifespan of RBC
90-120 days
61
Where is iron stored when in excess
Liver
62
What does iron do in bone marrow
Helps produce erythroblasts to form RBC
63
Transport of iron in plasma
Transferrin transport
64
Haem iron
Ferrous ion - Fe2+
65
Non haem iron
Ferric ion Fe3+
66
Physiological loss of iron
Pregnancy
Lactation
Menstruation
Cell loss
67
Pathological loss of iron
```
Bleeding
Peptic ulcers
Menorrhagia
surgery
Haematuria
```
68
Iron overload management
Phlebotomy
| Iron chelation
69
Megaloblastic anemia underlying defect
Defect in DNA synthesis (nucleotide synthesis or DNA polymerization) usually caused by vit B12 or folate deficiency
70
Vit B12 appearance
Red water soluble
71
Vit B12 source
Meat
Liver
Seafood
Dairy products with no plant source
72
Vit B12 aborsoption mechanism
R-binder-cubilin in saliva binds to food and get into stomach
HCl released from parietal cells and act on pepsinogen released by chief cells to form pepsin
Pepsin break down proteins and release vitB12
VitB12 protected from gastric environment of stomach by by binding R-binder
VitB12-R-binder complex gets into small intestine and vitB12 released from complex because no more acidic
VitB12 binds now intrinsic factors because they have ileum receptors for absorption. Vit b12 gets absorbed by forming this complex
73
Source of folic acid
```
Green vegetables
Fruits
Liver
Yeast
Groundnut
Beans
```
74
Site of absorption of folic acid
Proximal jejunum and duodenum
75
Functional form of folic acid
Tetrahydrofolate
76
Why is vit b12 important for folic acid
Helps free tetrahydrofolate from methyl tetrahydrofolate for conjugation reactions which helps in DNA Synthesis
77
Folate trap hypothesis
Deficiency of vit b12 can lead to interruption of folate inter conversion which will cause accumulation of methyl tetrahydrofolate
78
Causes of megaloblastic anemia
Vit B12 deficiency
Vit B12 metabolism abnormality
Folate deficiency
Folate abnormal metabolism
Defects in DNA synthesis
79
Causes of vit B12 deficiency
Inadequate diet (vegan, poverty imposed, breast fed children with pernicious anemia mothers)
Malabsorption in stomach (hypochlorydria which reduces HCl, chronic H pump inhibition, atrophic gastritis, pernicious anemia, partial or total gastrectomy, caustic mucosal destruction)
Intestinal malabsorption ( pancreatic insufficiency, zollinger Ellison syndrome, stasis syndromes, fish tapeworm, ileal resection, Crohn’s disease , cubilin receptor defect )
80
Folate deficiency cause
Inadequate diet intake ( poverty, famine, slimming diets, cooking techniques)
Increased folate use ( pregnancy, hyperemesis, prematurity, growth spurt
Excess loss ( dialysis, congenital heart failure)
Malabsorption ( congenital, sprue, gluten enteropathy)
Drugs ( alcohol, methotrexate, anticonvulsants, sulfasalazine)
81
Abnormalities in DNA synthesis
Lesch nyhan syndrome
Congenital dyserythropoietic anemia
Drugs
Erythroleukemia
Hydroxyurea
Mercaptopurine
82
Past medical history of megaloblastic anemia
```
Past abdominal surgery
Autoimmune disease
Veganism
Alcoholism
Epilepsy treatment
Hemolytic anemia
```
83
Neurologic symptoms of megaloblastic anemia
Darkened hands and feet
In both legs ( tingling, burning , numbness , falling over in dark low strength, altered sensation )
Memory loss
Psychosis
84
Physical examination of megaloblastic anemia
```
Pallor
Jaundice
Feeding state
Glossitis
Angular cheilosis
Hyperpigmentation
Vitiligo
Reduced sensation
Optic nerve neuropathy
Dementia
```
85
3 questions to ask for megaloblastic anemia
Is there megaloblastic anemia ?
Is it due to folate or b12 deficiency
What caused deficiencyl
86
To see megaloblastic anemia in lab you should see :
Full blood count : low Hb and high MCV , thrombocytopenia, neutropenia
Peripheral film : oval macrocytes, hypersegmented neutrophil
Bone marrow: megaloblasts, giants metamyelocytes, giant band cells
87
differential diagnosis of macrocytosis
```
Alcohol
Liver disease
Hypothyroidism
Myelodysplasia
Myeloma
Aplastic anemia
Pregnancy
Neonates
Hemolytic anemia
Zydovudine
Methotrexate
```
88
B12 and folate assays
First line tests (Serum b12/Serum and red cell folate)
Second line tests (homocysteine and methylmalonic acid test )
Homocysteine high => folate deficiency or b12
MMA => b12 deficiency
89
Treatment of folate deficiency
Folate replacement therapy
| Can be used in b12 deficiency anemia but can allow neurological symptoms of b12 deficiency to continue
90
B12 deficiency treatment
B12 replacement IM or SC for life
91
Dietary factors that favors iron absorption
Increased haem iron
Increased animal foods
Ferrous iron salts
92
Dietary factors that reduce iron absorption
Decreased haem iron
Increased non haem iron
Decreased animal food
Ferric iron salts
93
Luminal factors that promote haem absorption
Low molecular weight soluble chelates (vit c , sugars)
Ligand in meat
94
Luminal factors decreasing iron absorption
Alkaline substance (pancreatic secretion)
Insoluble iron complex
95
Systemic factors increasing iron absorption
```
Iron deficiency
Increased erythropoiesis
Ineffective erythropoiesis
Pregnancy
Hypoxia
```
96
Systemic factors decreasing iron absorption
Iron overload
Decreased erythropoiesis
Inflammatory disorders
97
Iron absorption metabolism explained
Haem iron ring bind to receptor on enterocyte
Haem iron penetrates cell
Haem oxygenase free the Fe2+
Fe3+ outside of cell becomes Fe2+ by ferric reductase
Fe2+ enter the cell by divalent métal transporter
All the Fe2+ get into labile iron pool
Some iron go for cell metabolism
Some iron get stored into enterocytes
Some iron get absorbed
To get into blood , iron goes through ferroportin channel.
Hephaestin associated to channel to transform Fe2+ to Fe3+ to allow absorption
Ceruloplasmin convert Fe2+ that escaped to Fe3+
Transferrin attaches Fe3+
98
How is ferroportin regulated by hepcidin
When hepcidin low , ferroportin opens
When hepcidin high, ferroportin closes
99
How can iron Anemia of chronic disease mimic iron deficiency anemia
In disease like cancer , cytokines increase hepcidin level which shuts down ferroportin Which decreases iron absorption
Blood iron low , but iron storage high
100
Iron level investigation
Serum ion
Transferrin saturation to see how much they are occupied in blood
Total iron bound in to see free transporters
Ferritin amount
101
Iron deficiency anemia lab findings
Serum ion low
Transferrin saturation low
Iron high
Ferritin low
Elevated transferrin
Hypochromia
Microcytosis
Aneamia
102
Anemia of chronic disease lab findings
Serum iron low
Transferrin saturation low
Total iron high
Ferritin normal level or high
103
Iron overload lab findings
Iron serum high
Transferrin high
Iron low
Ferritin high
104
Cause of iron deficiency anemia
Increased iron usage ( pregnancy, infancy , adolescence)
Blood loss
Malabsorption
Dietary inadequacy
Combinations of above
105
Most specific lab findings for iron deficiency anemia
Low ferritin levels
106
Stages of iron deficiency anemia
Reduced iron store
Iron deficient erythropoiesis
Iron deficient anémia
107
Clinical features of iron deficiency anemia
Koilonychia
| Angular cheilosis
108
Iron deficiency anemia management
Iron therapy
| Parentéral or Irak
109
Genetic haemochromatisis
Iron overload disease caused by increased iron absorption which can cause organ damage
110
Gene affected in genetic haemochromatosis
HFE gene associated with low hepcidin
| Type I
